


Coming Down

by CupidStrikes



Category: Voltron: Legendary Defender
Genre: Alien anatomy, Anal Sex, Biting, Bottom Shiro (Voltron), Enthusiastic Consent, Galra!Keith, Knotting, Lots of come, M/M, Marking, Some Size Kink
Language: English
Status: Completed
Published: 2016-10-03
Updated: 2016-10-03
Packaged: 2018-08-19 07:56:56
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 4,355
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/8196778
Author URL: https://archiveofourown.org/users/CupidStrikes/pseuds/CupidStrikes
Summary: Keith has a perfect vantage point as he watches Takashi Shirogane, ace pilot and all-round golden child, squirm and fight against his body's reaction to his touch.





	

**Author's Note:**

  * For [Fonbella](https://archiveofourown.org/users/Fonbella/gifts).



> Gift for the lovely Fonbella, and heartily inspired by this: http://pearldarling.tumblr.com/post/150598372242 (link very NSFW)
> 
> So here it is. My contribution to the fandom and by far the dirtiest thing I've ever written. Sorry not sorry.
> 
> Italics are Jealous Gods by Poets of the Fall. The rest of this sin is all mine.

**Coming Down**

 

_With every wall ablaze around us_  
_Calling out your name like it's now and never surrender_  
 _Victory is yours to claim_

 

“Shiro no-”

 

“Shiro yes.”

 

Keith's reply is lost in a moan as Shiro's mouth follows his jaw bone up to his ear and then continues up as smooth skin becomes furry. The fur is short and downy but doesn't stick to his tongue as he presses the flat of it against the ridged side, licking up to the top and taking the pointed tip into his mouth. The ear twitches. Once. Twice. Shiro laughs around it and follows so that it can't escape his mouth. He presses his teeth against it very lightly and is rewarded by Keith's sharp intake of breath.

 

“Shiro.”

 

He moves his mouth to the other ear, crowding Keith up against the edge of the bed and when Keith leans back into air and falls onto the mattress Shiro follows. He leans up and sucks the edge of Keith's left ear into his mouth, his left hand sliding up to gently rub at where the base of his right ear meets his hairline.

 

Keith mewls beneath him. His hips cant up and knock their groins together and Shiro closes his eyes tightly as he grits his teeth.

 

“You minx,”

 

Keith bats at him and Shiro laughs into the hollow where Keith's neck meets his shoulder. Shiro sits back when that shoulder twitches and Keith makes a half-movement away from him. He smirks, and the look Keith gives him in return is positively murderous, all narrowed eyes and the faintest pout of his lower lip as it becomes clear that this has done nothing to dampen Shiro's amusement, or his plan.

 

“Oh?”

 

“Don't you dare, Shiro-”

 

“Or what?”

 

Keith curls a knee up and presses his foot flat against Shiro's chest. The pressure is strong and something in Shiro's stomach thrills at it. He almost lets Keith push him all the way off before reaching under his knee and rubbing the tip of his middle finger across the crease there.

 

The reaction is immediate and Shiro has to brace himself against the wall to prevent himself from being thrown off the bed entirely.

 

“You are unbelievable.”

 

Keith looks up at his boyfriend and frowns when Shiro presses a hand over his nose and mouth. He sits up slowly on one hand and reaches out towards him, his hand brushing up against the cool metal of Shiro's prosthetic. He feels more than sees the tremors coursing over Shiro's shoulders at first, and as he focusses the shaking increases.

 

“Hey did I-”

 

He reaches to push Shiro's hand away so that he can get a better look-

 

-as Shiro snorts into his palm and tilts his head back as a helpless giggle leaves his lips.  


Keith scowls.

 

“I'm sorry, it's just...shit, Keith, your face-”

 

Shiro's explanation is lost in more giggles. Keith rolls his eyes and reaches up. He grabs Shiro's collar in both hands and in one smooth movement he has Shiro on his back on the bed and is straddling his hips, his knees bracing most of his weight against the bed.

 

“What about my face.”

 

He leans over Shiro and in close. Shiro's cheeks are flushed up to the scar across the bridge of his nose and as he bites his lower lip Keith leans in and presses their mouths together. His tongue pries that lip away from Shiro's teeth and pressing in deeper before withdrawing before Shiro can meet him. He sits back on his heels and shifts backwards just briefly enough to brush his rear against Shiro's crotch, and he grins savagely at Shiro when he feels the hardness there. Keith watches as Shiro's Adam's apple bobs down on a swallow as Keith's hand reaches backwards and traces the firm outline where the too-tight trousers have been pulled taut around the flesh.

 

“Cat got your tongue, Shiro?”

 

Keith asks, baring his teeth and licking the tip of a pointed canine to draw Shiro's attention in before he squeezes his erection. Shiro's next breath shakes into his lungs and is lost in a groan almost immediately when the warmth of Keith's palm is suddenly absent from his dick. Keith has a perfect vantage point as he watches Takashi Shirogane, ace pilot and all-round golden child, squirm and fight against his body's reaction to his touch.

 

Sitting back, Keith strips the tight black shirt off his body and tosses it away from the bed. It knocks something off his desk in its journey towards the floor, but they both ignore the clattering of metal on metal as Shiro surges up to meet Keith in a hard kiss that is more teeth than anything else. When Shiro pulls back his lips are swollen and there is a thin smear of red on his chin where the biting has drawn blood on one of them.

 

It's not long before they're both naked. Shiro wriggles out of his clothing with grace that no one pinned on his back out to have, and Keith shimmies out of his jeans with less finesse but more speed. He leaves his perch on Shiro's hips to make it easier, stripping off his boxers and socks in the same movement and leaving them where they fall. He turns back to face Shiro with a grin, palming his cock slowly-

 

only to have Shiro's underwear hit him in the chest.

 

Keith watches as the offending fabric bounces off and hits the floor with barely a sound. He looks back up and raises an eyebrow slowly for effect at Shiro. Shiro whom is trying very desperately and failing spectacularly at not laughing.

 

“Was there any need?”

 

“Well,” Shiro begins and breaks off into a snigger, “I took them off for you.”

 

Keith slides the little pile of black fabric to one side with the very tip of his big toe. He meets Shiro's gaze with a smile then wrinkles his nose up for effect.

 

“I don't know where they've been,”

 

“Nowhere your mouth hasn't been, babe,”

 

Shiro has clearly been hanging around Lance too long.

 

Keith shakes his head and hides a grin as he joins Shiro on the bed again, stretching out over him and taking Shiro's wrists in his hands, pinning them above his head. Shiro shifts. Tests the hold out of habit more than anything else and Keith holds still as he lets Shiro move his hands just a little off the mattress before resting more of his weight on him and leaning in to kiss him again. Shiro's next noise, some bastardisation of a laugh and a moan both, is lost as Keith presses his tongue into his mouth and his dick against Shiro's.

 

He lets one hand free and shivers as it feels Shiro's human fingers card through his hair, the sde of his thumb stroking down the side of his ear. He had been worried that his Galra features would put Shiro off, all things considered, and yet... Keith tilted his head back a fraction as that thumb swept over the sensitive skin at the base of his ear making him twitch it involuntarily. Shiro chuckles, the sound low in his throat, and then that hand is moving. Keith feels it track down his back and lower until Shiro slips it between them and Keith's entire body twitches one fingertip brushes the base of his cock and to the swollen flesh below it.

 

They haven't touched on this before.

 

It wasn't like Keith had expected creatures like the Galra to have the same reproductive organs as humans (and his thoughts hadn't even ever gone there before they were forced to), but he hadn't expected the differences to be so....much. Thankfully the colour of his dick hadn't changed with the shape; he wasn't sure how he would have reacted if he had woken up to purple junk as well as big furry ears and the other changes...

 

For one, he now had some sort of swelling at the base of his cock. He had had a few errant erections since the transformation had begun, but it hadn't ever swelled up much, not like it was now as he rutted against Shiro slowly, the tip of his cock now leaking enough precome to allow this without any unwanted friction.

 

For two, well...

 

Shiro nudges at him, and Keith initially protests the movement until Shiro whispers _wanna blow you_ into his ear and then he can't move fast enough. Shiro's laugh vibrates through his chest as he wraps an arm around Keith and rolls them over, leaving Keith on his back as he guides himself down the bed. Breath catching in his throat, Keith fists his hands in the bedsheets and swallows hard as Shiro breaths over the moist tip of his cock.

 

And then Shiro's hands are on the base and on the lump there, and then there is a tongue playing over the smooth skin and the pointed tip, down to the slight ridges lower on the shaft. Keith snarls into the pillow, his knees twitching uselessly as he fights to keep from crowding Shiro. He reaches down with a shaking hand once he's sure he has a hold on himself,

 

and drops it to clutch at the mattress when Shiro moves his head and presses open-mouthed kisses to the skin at the base of his cock where the swelling begins.

 

“Kiss your mother with that mouth?”

 

Shiro grins at him and Keith is tempted to shove him right off the bed.

 

He doesn't.

 

Instead he reaches over, his fingers steady, and he grasps Shiro's shoulder, staring up into his eyes.

 

“Don't fucking tease me, Shirogane, I swear to-aahn...fuck...!”

 

He lets go abruptly in favour of clapping the hand over his mouth to smother the noise as Shiro swallows him down in one movement, and it's a miracle he doesn't choke when Keith arches clear off the bed. When Keith's eyes uncross enough for him to see, he looks down and, oh god that's a mistake because Shiro is smiling around his dick when their eyes meet. Keith feels a violent shiver run up his body and there is no way that Shiro hasn't felt it too, and he's pulling off.

 

Keith opens his mouth but shuts it abruptly when Shiro's tongue swipes a hot line across the skin of his...whatever ( _knot,_ his brain supplies, the word plucked from some vestige of knowledge he had picked up unconsciously, you have a _mating_ _knot_ ). His knees quiver and he grasps Shiro's for support as his head ducks forward, tucking up against his chest as his breath comes out in shakey pants.

 

“Keith? Keith what-”

 

“Fuck, do that again.”

 

Shiro laughs as he does it again. Keith feels it vibrate through his tongue and he's not sure how he remains upright but he is thankful that he doesn't embarrass himself completely, at least. That tongue moves over him again and again until the area is wet with saliva and Keith feels tingly as it feels the cool air in the room more acutely than ever.

 

Then Shiro pulls away.

 

“Shiro”

 

Keith isn't whining, and he's definitely not pouting. Not at all. He reaches out to Shiro with the intention of dragging his face right back in between his legs, and when Shiro ducks away Keith is sure the noise he makes is more of a whimper than a growl.

 

Shiro, the git, grins at him and slides a hand down his chest slowly, catching Keith's attention, and then grips his own cock. He strokes it languidly, and when the light catches on a bead of precum sliding free under his thumb, Keith loses it.

 

He surges forward, one hand curling around Shiro's forearm to pause those movements as their mouths crash together. They're both bleeding somewhere now. Keith doesn't care. He nudges Shiro towards the bed, his hand remaining on his arm until they stumble down onto the mattress.

Keith struggles on top of Shiro, pressing the balls of his palms into his shoulders to keep the other man from wriggling free.

 

“Oh no you don't. No more teasing.”

 

Shiro grins at him and bucks his hips up hard enough to send Keith offbalance and sprawling over his chest.

 

“Or what?”

 

Keith shifts his head and leans in just a little further to latch onto Shiro's neck. He nips the flesh there and then moves up and catches the side of his ear lobe between his teeth. One hand goes to Shiro's chest as Keith sucks the lobe into his mouth, skirting his teeth up it as Shiro goes still beneath him. He replaces teeth with tongue and smiles when Shiro is all movement again, feeling the reverberations of all the moans that Shiro keeps behind gritted teeth.

 

“Need you now Keith.”

 

That gives him pause and he releases Shiro's ear to sit back, propping himself up on one elbow so that he can look into Shiro's face. His hairline is dark with sweat and his cheeks are flushed all the way up and past his scar and for a moment it's almost invisible in the low light. Bracing a hand in the space beside Shiro's head, Keith stoops down and kisses the very edge of it where it bisects the smooth skin of his cheek. He feels a warm, heavy weight settle over his lower back as Shiro curls his right arm around him.

 

“Love you,”

 

“Back atcha,”

 

Shiro flicks the edge of Keith's ear and snickers when he sits back with a squeak of surprise.

 

“All right, enough with the mushy and fuck me already.”

 

Well, no arguing with that.

 

“Yes, sir,”

 

Shiro is pushing a small glass bottle into Keith's hand and he lounges back against the pillows and Keith opens his mouth to make a comment about keeping him up. Closes it again when Shiro's knees part. He shifts back on his knees to give Shiro room and then shuffles forward, one hand brushing against Shiro's thigh as he does so. Keith's thumb rubs up against the scar that lines the crease where hip and thigh meet and he keeps eye contact as his fingers brush up against Shiro's perineum.

 

He twitches. The motion is controlled, barely, and Keith feels it only because he knows to wait for it.

 

It passes and Keith moves his fingers deeper, lower, and Shiro is still. He looks at Keith and his eyes are nearly black; the pupils blown-wide with lust, and the silver of his irises a barely visible silver ring around them. Keith knows this part well, and he can almost forget that they are on an alien spaceship, millions of light years away from earth, and not in Shiro's bunk in the Galaxy Garrison, or his in the little desert shack they made their haven, or-

 

Shiro groans, the sound loud in the open air as it derails Keith's train of thought.

 

He smiles, ducking his head down so that Shiro won't see. Shiro wasn't so loud back then, and Keith smiles as he removes his fingers and moves up his boyfriend's body to kiss him and finds him open-mouthed and waiting. He hasn't had to tease Shiro out of muffling himself since Kerberos, since the scar on his nose and the silver in his hair, and Keith takes it. He takes the noises out of Shiro's throat with his lips and tongue and swallows them greedily.

 

Then Shiro's fingers are on his dick and Keith breaks the kiss. Pulls back and stares down at Shiro. Holds eye contact as he feels the tip press against Shiro's body, and then he's being guided in and heatheatheat everywhere and Keith shivers despite the warmth that is radiating out to every inch of him. Every time still feels like the first, even so, Keith is hyper-sensitive from nerves. He searches Shiro's expression for disgust, discomfort, dis-something – his anatomy has changed too much and surely-

 

Shiro smiles crookedly at him and curls his arm around Keith, the metal cool and burning against his flushed skin. He bites a swollen lip as his eyes slip closed and Keith watches a single droplet of moisture bead at the corner of Shiro's eye and slip down his cheek, leaving a faint smudge as it displaces his eyeliner. He catches it on his tongue before it reaches Shiro's jaw and when Shiro's eyes open, half-lidded, Keith winks and slips forward.

 

Keith knows Shiro's body, and it's instinct-easy to draw out the noises that make them both thankful for the superior sound-proofing in the castle. He stills once he feels the sensitive swell of his knot press up against Shiro's body and can't help a glance down at where they are joined. He hears Shiro echo his groan, and when Keith looks up he can see that Shiro is staring at the same thing.

 

“Still okay?” He leans his weight on one hand so that he can touch Shiro with the other. His thumb drags across the soft skin of Shiro's cheek, tracing the firm bone beneath. Repeats the motion and starts at the comet-tail end of the scar. Shiro nods, the movement gentle enough that it doesn't displace Keith's hand.

 

“How could I not be?”

 

The reply is soft enough that Keith almost misses it, and he has to look into Shiro's eyes to confirm that he even hear it at all and hadn't imagined it. Shiro is smiling still, but it's somehow more intense than before. Moonrays peaking between clouds. Keith ducks in and kisses him his hand slipping down to cradle against the side of Shiro's head as he does so. Keith can think of many ways that this could not be okay, that Shiro could not be okay beneath him and letting Keith bear witness and participant to such a vulnerability and openness and yet....

 

And yet, here they are, and something thrills through Keith. He recognises it, even now out of the chaos of battle, Keith feels it like an old friend, like Shiro coming home to him, and he kisses Shiro again as he rocks in a little deeper and then out, just shifting an inch or two back and forth as he waits for the last bastion of self-control to crumble. They're nearly there, and on the cusp of a plea, Keith pulls out almost to the tip, hears Shiro's breath hitch in loss-

 

And then he slams in home on the exhale.

 

The noise torn from Shiro's throat is all base instinct and half-syllable with distraction. Keith answers it in turn. Smiles down at Shiro and kisses him breathless as his hips fall into a familiar, comfortable rhythm. His new anatomy hasn't affected this, at least, and he's grateful for it. Grateful that he can still pull these noises out of Shiro. That whilst his body might have forgotten about being human entirely, it still remembers Shiro, and remembers the ways to make him feel good.

 

And it is good, it's so good, and Keith feels like he's glowing just a little bit with how sensitive he is. He can feel every bead of sweat on his body, and the faint chill of the Castle air as it moves around them in an endless cycle from the air conditioning. Beneath him, Shiro is a mess, and Keith loves it, tells him so as he smooths his hands over Shiro's chest.

 

“Keith.”

 

When Shiro speaks there is a serious note in his voice that slows Keith's hips and makes him look up at his face. His nether parts ache fiercely at the interruption but he ignores it.

 

“Too much?”

 

Shiro grins at him and if anything the flush on his cheeks is getting darker. He swallows, and Keith's eyes flick down to where a single drop of sweat trickles down over Shiro's throat. His tongue presses against the backs of his pointed teeth and Keith is half-way down to lick it up when he catches himself. When he looks back up at Shiro, he doesn't seem to have noticed, or if he has he doesn't care.

 

Strong arms wrap firmly around Keith's shoulders and one of Shiro's heels digs into his butt, and Keith groans aloud as it forces him even deeper inside Shiro, his knot squeezed between them.

 

“Do it.”

 

It's like thinking through molasses.

 

“What? But we are...”

 

There's probably some other meaning but too much of his blood has gone South and Keith can't think beyond the literal meaning. He feels Shiro's chest vibrate with a laugh. It's not unkind, never is with Shiro, and Keith watches him patiently, holds as still as he possibly can with Shiro shaking around him.

 

“The knot. Put it in. I want it.”

 

Three simple sentences. Eight words. Nothing fancy or special, and yet Keith feels as if fireworks have gone off in his brain. Something in him strikes hot and fast and he growls out a moan as he surges forward, almost missing the look of happy surprise on Shiro's face at the sudden change.

 

“Please, Keith.”

 

Keith looks at Shiro helplessly as another strangled noise tears itself out of his throat unconsciously. He's grinning again, the git, and Keith pulls a face at him as leans up, bracing himself on Shiro's shoulder and the mattress as he fucks him with renewed vigour and purpose; he's going to fuck that look right off of Shiro's face, damnit, and....and....and...

 

And Shiro is saying something again but Keith can't make it out over the thrumming in his ears from his own racing heart, and he barely hears it taper off into a single note as Keith presses forward harder and feels the knot slip in and suddenly everything is white and then black, and someone is making a low, incoherent noise and Keith thinks it might be him but he can't be sure and he shakes his head to clear it because shit, shit, shit, everything centres on the point where he and Shiro are joined and he's being squeezed so tightly he worries the circulation will be cut off even as he's coming harder than he ever has before and Keith strains against it even so because -

 

“ShiroShiroShiroShiro, fuckfuck...”

  
  
\- And Keith clears his head long enough to hear a broken little whine slip out of Shiro's throat, and when he looks down, suddenly feeling hollow with terror that he's hurt him, Shiro is smiling at him. No longer smug, with his eyeliner smudged across his temples and blotches of dark red and pink all over his face and up his chest and neck, and Keith feels his breath catch in his throat because Shiro looks wrecked and that's all him. All his doing. He feels himself tremble with it, and Shiro lets out a keening noise between his bitten lips, his head tilting back and exposing more of his throat and Keith can't help himself this time as he leans down and bites the junction between neck and shoulder. Shiro shakes beneath him, his arms tightening periodically around Keith's shoulders as he struggles against the powerful aftershocks.

 

Shiro's Galratech hand rubs abstract little patterns into Keith's back, the metal warmed through and making Keith shiver and twitch slightly despite how hollowed out and dried up he feels. Shiro shifts beneath him, twitching one leg and Keith moves with him. He expects his softened cock to slip out, but nothing moves and a surprised little gasp leaves Keith at the pulse of pleasure that darts up his spine.

 

Ah, right, the knot.

 

He looks down at Shiro slowly, wetting his dry lips as he tries to think of words for an explanation. Shiro is watching him through half-lidded eyes and the look he gives Keith just about dries up the rest of the moisture in his mouth.

 

“We're stuck.”

 

Keith feels like an idiot the moment the words leave his mouth, but it's all he can think of right now, his brain compromised by knowledge and sensation, and he feels filthy and wonderful all at once.

 

Fingers brush up against the base of his knot and Keith groans helplessly as they press up against where he and Shiro are still joined. He feels that finger smear something over his skin, and the recognition has him pressing his face into Shiro's neck and trembling despite how empty he is.

 

“I noticed.”

 

Keith doesn't even react physically to Shiro's smug tone, just makes an irritated noise as two more of Shiro's fingers join in their exploration of Keith's new anatomy. He can feel, if he concentrates, little trickles of come escaping from between them with each twitch and shift as they come down together.

 

“Is it okay?”

 

Keith sits back on an elbow, barely biting down on a groan as the movement seats him even deeper inside Shiro. He keeps his face still, neutral, and when Shiro's right hand finds his left he lets their fingers thread together.

 

“Mm, more than,”

 

He bites his lip harder at the open, raw little smile on Shiro's face and then leans in to kiss it right off his lips, giddy with relief. They relax into each other afterwards, breathing through the descent, Keith slowly shifting his hips now and then as he feels the knot begin to deflate. He slides free with an obscene little wet noise that has both of them groaning, and Shiro presses a hand to his mouth to stifle a gasp, his other hand gripping Keith's fingers tighter, and just as Keith is about to ask if he is hurt after all, Shiro speaks through the incoherent noises, his voice quivering and rough.

 

“Just....just how much did you come, Keith?”

 

He's grinning despite it, and when Keith works up the courage to look down he swallows hard against another pang of arousal, a little thrill of _marked_ , and of _mineminemine_ , and he looks back up into Shiro's wrecked expression with as much composure as he can manage in that moment.

 

“We are definitely gonna have to change the sheets.”


End file.
